Fabric treatment processes

ABSTRACT

Fabric is treated with a detergent solution and then dried to form a pliable protective coating of detergent on the fabric. The treated fabric is subsequently washed after use simply by rinsing in water, when the detergent coating, which may incorporate chemical agitators, is activated to wash the fabric. A fresh detergent coating can then be applied to the clean fabric.

IP8309 XE 51658 1672 v---" uwatCB I Swayn [4 1 Mar. 21, 1972 1541 FABRIC TREATMENT PROCESSES [72] Inventor: Francis H. Swayn, 5 Elton Avenue, Blun- [56] Re erences cued deilsands, Liverpool 23, England UNITED STATES PATENTS [22] Filed: Nov. 27, 1968 3,121,249 2/1964 Affleck et a1. ..252/91 X [2!] Appl' Primary Examiner-Mayer Weinblatt AttorneyMichae1 S. Striker [30] Foreign A lication Priorit Data pp y [57] ABSTRACT Oct. 3, 1968 Great Britain ..46,886/68 1, 1967 Great Britain "54843/67 Fabric is treated with a detergent solution and then dried to form a phable protectlve coating of detergent on the fabric. 52 us. c1 ..8/137, 8/1 10, 8/111, T em Subsequently P' by 117/47 1 17/66 1 17,139 5 CO rinsing in water, when the detergent coating, WhlCh may incor- 1m Cl 808; porate chemical agitators, is activated to wash the fabric. A g I l l s s I l l s s a l I I l I e e e s s l s s I v I I s f h d t t t b l t l f l 58 Field of Search ..8/137, 110, 111;117/139.5 c0, res 6 ma mg can e app 6 C can abm 1 17/66, 47 2 Claims, 3 Drawing Figures Patented March 21, 1972 2 Sheets-Sheet 1 I I I I I I I I gt Iwxum 0 I rm/m :4. 54mm) FABRIC TREATMENT PROCESSES This invention relates to processes of treating fabric, and to processes of cleaning fabric articles which have been so treated.

The conventional washing process for a fabric entails agitation of the fabric in a detergent liquor, followed by rinsing in clean water and drying. An object of the present invention is to provide a fabric treatment process which is relatively simple, and which at the same time affords some protection to the fabric between washing processes.

Broadly, the present invention provides a process of treating a fabric in which a water-soluble detergent solution is applied to the fabric and the fabric is then dried, the detergent being such that upon drying of the fabric the detergent remains, forming a pliable protective coating on the fabric. When a fabric which has been treated in this way is used, the protective coating tends to prevent the penetration of soiling matter to the fibers of the fabric itself, and the soiling matter is confined predominantly to the coating. When therefore, a fabric article which has been treated by this process is to be washed, it is merely necessary to rinse the article in clean water: the detergent coating is then activated, carrying into the water any soiling matter and at the same time cleaning the fabric.

The detergent should be a nonionic detergent with pH value not greater than 6. The detergent may include, as desired, an optical brightener. A preferred addition to the detergent is an effervescent agent which remains in the protective coating on drying of the fabric: when the fabric (in a soiled condition) is subsequently rinsed in clean water the effervescent agent is activated, and assists the washing action of the detergent coating, mechanical agitation being unnecessary.

The invention also includes within its scope a fabric which has been treated by the process defined above, and further includes a process for washing a soiled fabric article which has been treated by said process. According to such a washing process the article is first rinsed in clean water to remove its protective coating of detergent and clean the article, and the clean article then subjected to a further application of the water-soluble detergent in solution, and dried to leave a fresh protective coating of said detergent on the fabric.

Preferably, before rinsing in clean water, the detergent coating is activated by first applying a hydrogen peroxide solution to the fabric, followed by an oxygen-release agent effective to release oxygen in the detergent coating.

The invention also provides apparatus for washing a soiled fabric article which has been treatedso as to provide it with a protective coating of detergent, said apparatus comprising means for rinsing the article in clean water to remove the protective coating of detergent and clean the article, means for applying a detergent solution to the cleaned article, and drying means for drying the article to leave a fresh protective coating of said detergent on the fabric.

Apparatus according to one embodiment of the invention comprises a tank, a reservoir for the detergent solution and pump means for circulating detergent solution between the reservoir and the tank. A supply of the detergent solution would be maintained in the reservoir. Since in the process according to the invention the detergent solution is applied to the clean fabric only after the rinse water containing the soiling matter has been removed, the detergent solution itself does not become contaminated, and accordingly the solution remaining in the tank after the coating has been applied to the clean fabric can be recirculated to the reservoir for reuse. Consequently there is minimal wastage of detergent as compared with conventional washing processes. A power-driven agitator may be provided in the tank in the conventional manner.

An alternative apparatus for carrying out the cleaning and treatment process according to the invention includes at least two tanks adapted to contain clean rinsing water and a solution of the said detergent respectively, and conveyor means for conveying the article through said respective tanks in succession and thence to the drying means.

According to the invention a fabric to be treated is first cleaned and then a detergent liquor is applied thereto, either by immersing the fabric in the liquor or by spraying the liquor on to the fabric. Water is then extracted from the fabric to reduce the moisture content so that it lies within the range 35 to 60 percent of the dry weight of the fabric. Partial drying is then effected, for example, in a tumbler drier, for a period of l to 10 minutes, or in a conveyor drier, or by natural means, to reduce the moisture content to the range 45 to 25 percent of the dry weight of the fabric. The fabric will then contain sufficient detergent to form, when the fabric is finished, a thin waxy film coating on the fibers of the fabric. This coating is pliable, so that it forms a protective layer on the fabric which layer is not broken when the fabric is folded and creased in normal use.

Consequently, when the treated fabric is used, the detergent coating to some extent prevents the fabric itself from becoming soiled, soiling matter being absorbed by, and held in.

suspension in, the coating. To clean the treated fabric it is sufficient merely to immerse the fabric in, or spray it with, clean water. The detergent is activated by the water and any chemical agitator present is also activated, so that the detergentcarries into the water the suspended soiling matter, at the same time cleaning the surface of the fabric to a state of reflectance acceptable by conventional standards.

A preferred nonionic detergent is a material, used as a base for conventional detergents, and having the formula:

Alternatively, detergent material having the following formula may, for example, be used:

C, H O(CH CH O) H+C ,,H ,O(CH CH O) H This detergent is used to form the detergent liquor by solution in water in concentrations typically between 2 and 30 percent by weight (according to the nature and quantity of fabric to be treated). The concentration of the detergent liquor is conveniently assessed by using an hydrometer to measure its specific gravity.

Additives to the detergent may include optical brighteners, as known per se and chemical agitators or effervescent agents, for example agents containing peroxide groups.

The cleaning of the treated fabric is effected without requiring the addition of any detergents, soap builders or soap tothe rinsing water, all the detergent necessary to effect cleaning being supplied by the previously applied fabric coating.

Furthermore, the fabric cleaning treatment with clean water Where a chemical agitator is present in the detergent, this may be relied upon alone to produce the requisite agitation of the detergent coating to effect cleaning of the fabric, while in the absence .of a chemical agitator, mechanical agitation is used. if desired, both chemical and mechanical agitation may be used.

As an alternative to providing a chemical agitator in the detergent coating, the detergent may be activated immediately prior to the treatment with clean water by first saturating the detergent-coated fabric with a solution of ,diluted hydrogen peroxide, followed by the addition of an oxygen-release ageni, suitably sodium hydrosulphite (NaSO). Oxygen is released from the hydrogen peroxide by the action of the sodium hydrosulphite. This oxygen acts upon the detergent coating to cause frothing of the latter by an effervescent action, in turn causing removal of the detergent along with soiling matter contained in the coated fabric.

The treatment process according to the invention may be used to form a protective detergent coating on fabric which has been initially cleaned by any convenient process. Usually, however, the treatment will be applied to soiled fabric articles which have previously been provided with a protective coating, and in this case the treatment proceeds in two stages, a first rinsing stage, using clean water, in which the soiled detergent coating is removed and the fabric cleaned, with or without chemical agitation as described above, and a second treatment stage in which the clean fabric is coated with fresh detergent and dried to form a fresh detergent coating, also as previously described, with which the fabric is finished.

The invention will be more clearly understood from the following description, given by way of example only, with reference to the accompanying drawings, in which:

FIG. 1 illustrates diagrammatically in section a domestic washing machine converted for operating the process according to the invention;

HO. 2 illustrates diagrammatically in plan apparatus for effecting continuous treatment of articles according to the invention, and

FIG. 3 illustrates diagrammatically an alternative form of apparatus according to the invention.

FIG. 1 illustrates diagrammatically how a conventional domestic and commercial washing or laundering equipment may be adapted readily to carry out the process according to the invention. Thus a domestic washing machine M having a wash tank T and a pump P is adapted to by providing a storage reservoir R for containing a supply of the detergent liquor, made up to a predetermined concentration, as described above. The reservoir R is connected through a suitable valve or cock V, (which may, for example, be pneumatically or electromagnetically operated) to the wash tank T, a pump or pumps, which in this example comprises the normal pump P of the washing machine M, being arranged to fill the tank T with the detergent liquor or to return the liquor from the tank T to the reservoir R as desired when the valve V, is open. The machine M has a conventional drain valve V through which the pump P may pump water from the tank T to a waste outlet In order to wash soiled articles which have had a previous detergent coating applied thereto by the process according to the invention the wash tank T is first filled with warm or cold clean water from a mains supply S, and the soiled articles immersed therein. Both valves V, and V are closed. After agitation, conveniently by means of a powered agitator A in the tank T, valve V is opened and the now dirty water is pumped out by the pump P to the waste outlet W. Valve V is then closed and V, opened to fill the tank T with the detergent liquor from the reservoir R. The articles are then removed from the tank T and dried as described previously and the detergent liquor is then returned to the storage reservoir R by the pump P. The apparatus is then ready for reuse.

The amount of detergent liquor used up in one treatment cycle is slight, and liquor in the storage reservoir R, which conveniently has a contents gauge, is from time to time made up to the requisite volume and concentration through a filler inlet F.

On a more industrial scale, a plant for processing fabric articles, for example wearing apparal, in accordance with the invention may be designed to operate on a continuous basis.

In one form such a plant is illustrated diagrammatically in FIG. 2 and comprises a series of tanks with an endless conveyor C for transferring articles, singly or in batches, from one tank to the next in sequence. The path of the conveyor C is indicated by broken lines. Articles enter the plant where indicated by arrow land are withdrawn where indicated by arrow 0.

A first tank 1 1n the sequence contains a detergent activating liquor, in the form of a dilute solution of hydrogen peroxide, and a second tank 2 contains an oxygen-release agent, in this example a dilute solution of sodium hydrosulphite. A third tank 3 contains clean water which is continuously or periodically replenished, and a fourth .tank 4 contains the detergent liquor referred to previously.

Between the third and fourth tanks 3, 4, the article-carrying conveyor C passes through a final rinse compartment 5 in which the articles are sprayed with fresh water. Water collecting in the bottom of the compartment 5 is passed to the third tank 3 before running to waste.

After the articles have been immersed in the detergent liquor they are removed by the conveyor C to a drying chamber 6 through which the articles pass continuously, the finished articles being removed at O. The drying chamber 6 may, for example, comprise a compartment fitted with electrical heaters or steam-heated pipes 60.

Respective drip tray areas 8 are provided between successive tanks and compartments of the apparatus.

FIG. 3 illustrates an alternative form of article processing plant comprising a compartment 10 defined in a box arrangement or cabinet and provided with a number of spray nozzles 11. A continuously moving conveyor 12 carries articles 13 to be processed through the compartment in the direction of arrow 14 so that the articles are sprayed by successive nozzles 11 or groups of nozzles. Nozzles 11A at the inlet end of the compartment 10 spray warm or cold clean water for removing the old detergent coating, the resulting dirty water being collected and passing to a waste outlet W. Nozzles 118 at the discharge end of the compartment l0 spray the detergent liquor on to the articles 13, a suitable drain outlet 15 being provided in the base of this part of the compartment to recover, for recirculation to the nozzles 11B, the detergent liquor which does not adhere to the articles 13. The conveyor 12 leads the articles from the final spray stage through a heated drying space 16 where the treated articles are dried as described previously. If desired, the rinsing nozzles 11A may be preceded by two groups of nozzles spraying successively a hydrogen peroxide solution and a sodium hydrosulphite solution on to the articles 13 before the latter are subjected to the clean water rinse, so as to activate the detergent as described previously.

I claim:

1. A process for washing a soiled fabric article to which a pliable protective surface coating of nonionic water-soluble detergent having a pH value not greater than 6.0 has been applied, comprising the steps of rinsing the article in clean water to remove the protective surface coating of detergent and at the same time clean the article; applying a solution of the said detergent to the clean article; and drying the article to form a fresh protective coating of said detergent on the fabric, wherein said detergent is based on a fatty alcohol and ethylene oxide and has the formula: C, H O(CH CH O),, H and 1s a1 2 2 )so 2. A process according to claim 1 wherein said pliable protective surface coating of detergent is formed initially on the fabric article by applying a solution in water of the said nonionic detergent to the fabric and subsequently drying the fabric to leave the detergent as a pliable protective coating thereon. 

2. A process according to claim 1 wherein said pliable protective surface coating of detergent is formed initially on the fabric article by applying a solution in water of the said nonionic detergent to the fabric and subsequently drying the fabric to leave the detergent as a pliable protective coating thereon. 